Just a few years ago, you would never see such a disparity in votes vs comments. But these days, this is pretty much the norm. I've seen posts with 10K+ upvotes and no more than 80 comments.
I'd say in about 2 years, the entire place is going to be bots with AI generated content that try to mimic "real users" using their new Dynamic Product Ads tool. Not sure how that's legal as I thought ads needed to be marked or differentiated from regular content, but here we are.
The future looks bleak and AI even bleaker. Because it's going to be used against us to make the rich richer and not to make our lives better.
In addition to factors already mentioned by other users, I believe that there are also social/cultural reasons for that lack of engagement.
Commenting in Reddit is like stepping on a mine field - no matter how innocuous your comments are, you're bound to have users there assuming words into your mouth to screech at you. Plus all the "ackshyually", one-upping, "wah TL;DR!" (i.e. "I'm entitled to an abridged version of what you said, even if you likely spent far more time writing your comment than I would reading it").
Eventually you say "why bother commenting? Just to get a headache?" and stop commenting altogether.
It's also filled with repeat comments. Most posts you read a few top comments and their threads. But then it quickly becomes other people just commenting the same exact thing.
It's just not worth looking at comments there.
Don't even get me started on that. I made a post that blew up (7k upvotes) and literally the entire comments section was the same responses. Out of the 100s that replied, only 10% or less were novel.